Model #: (004456-2)
Propane or Natural Gas: Propane
Length of gas pipe feeding the generator: 10 ft
Size of gas pipe feeding the generator: ¾? Not a frequency issue anyway.
How long since the last full maintenance: if you mean the minimal list in the owners manual, yearly.
How long have you experienced this problem: Don’t know as it was identified during testing for voltage regulator replacement. Unit is usually lightly loaded so it would operate within tolerances for my application but something is wrong.

Description of problem:
12 Kw unit has at least 300 hours on it. It is usually lightly loaded. Had an over voltage which blew up my house furnace. Paid 800 bucks to get the same voltage regulator installed. Read that they had upgraded the regulator so ordered the new number per this website’s ‘sticky’. Finally decided to replace it so both regulators should be fully functional.

1. Unit operates at rated frequency and voltage at no load
2. Unit maintains adequate frequency but drops voltage during heavy load. Testing values below and these values were the same for both regulators:

Speed No Load Values:
Hz= 63
Volts= 252 VAC

Loaded Values (T1= 42 amps T2= 39.6 amps):
Hz= 58.3
Volts L-L= 212 VAC
Volts L-N= 106 VAC

When loaded to only 21 amps each phase, the voltage had dropped to 224 volts. These test values violate the stated ‘Voltage line to neutral will equal two times output frequency’ Again, this occurred using either of the voltage regulators so the problem is elsewhere.

Steps you have taken to resolve problem:
I see no mention of when to replace the brushes and that is my next step. Comments or insights? Thanks, Toukow